My 7-month-old DS hates what he sees as the "wide open space" in his cotbed! During the day he (and his twin brother) naps in his old carrycot, which he's virtually outgrown (think Dracula in his coffin, and that's about the same sort of snug fit his carrycot is for him!). I think the snugness makes him feel safe, and he usually goes to sleep instantly.
However, at night, he and his twin are in cotbeds. They did share a cot, but ran out of space and were annoying each other so we separated them. Unlike his twin, who settles pretty easily, DS tosses and turns, startles a lot with his arms flailing, and generally seems "lost" in the space of the cotbed as opposed to his cosy carrycot. He's in a gro-bag and doesn't have cot bumpers etc. Generally the only way to settle him is to lie down in our bed with him, holding him next to me until he falls asleep. How can I make him feel more secure in his cot, like he feels in his carrycot?